def do_fixed(data, length=2):
    return f"%.{length}" % data

def do_test(data):
    return f"{data}元"

def do_mobile(data, dot="*"):
    return data[:3] + dot + data[-4:]


FILTERS = {
    "fixed": do_fixed,
    "test": do_test,
    "mobile" : do_mobile,
}

if __name__ == '__main__':
    ret = do_fixed(10)
    print(ret)